Silk screen press



March 27, 1962 J. J. NICHOLSON SILK SCREEN PRESS '7 Sheets-Sheet 1 FiledJuly 20, 1959 INVENTOR. JEROME J. NICHOLSON BY 2 7 ATTORNEY N .o w 3 w I...+...l...... wjulvvnauwlsnfiufl ww mm o 5 8 mm m 2?? o I N NQ m on gN.

March 27, 1962 J. J. NICHOLSON SILK SCREEN PRESS 7 Sheets-Sheet 2 FiledJuly 20, 1959 INVENTOR. Janene J. \QHQLSON;

ORNY

March 27, 1962 J. NICHOLSON 3,026,794

SILK SCREEN PRESS Filed July 20, 1959 7 Sheets-Sheet 3 mmvrm JEROMEJ.N\cH0Lson BY I ATTGRNEY March 27, 1962 J. J. NICHOLSON SILK SCREENPRESS 7 Sheets-Sheet 4 Filed July 20, 1959 INVENTOR.

O 0 n Janene J. Nucuousou ATTORNEY March 27, 1962 J. J. NICHOI SON SILKSCREEN PRESS 7 Sheets-Sheet 5 Filed July 20, 1959 g mm NQ mm INVENTOR.JEROME J. NICHOLSON ATTORNEY March 27, 1962 J. J. NICHOLSON 3, ,7

SILK SCREEN PRESS Filed July 20, 1959 '7 Sheets-Sheet 6 I I I l I I I II l I I I I l I I [I I I I .l l I I l I I 9 |o6 VENTOR.

I JEROME J. NmHoLsoN A-r-rgnuav March 27, 1962 J. J. NICHOLSON SILKSCREEN PRESS 7 Sheets-Sheet 7 Filed July 20, 1959 INVENTOR. JEROME J.NlCHOLSON ATTORNEY United States Patent 3,026,794 SILK SCREEN PRESSIerome J. Nicholson, Milwaukee, Wis, assignor to Kubin- NicholsonCorporation, Milwaukee, Wis., a corporation of Wisconsin Filed July 20,1959, Ser. No. 828,377 7 Claims. (Cl. 101-123) This invention relates toan automatic silk screen press.

Silk screen printing is limited in its application to the small ordertype of job due to its slow rate of hand operation. Since silk screenprinting is a manual operation, economy of operation is dependent on theability of the operator. In all attempts to increase the rate ofproduction of the operator, semi-automatic devices have been usedprimarily to aid the operator in various phases of the printing processsuch as opening and closing the screen and carrying away the printedmaterial after printing. Attempts at using fully automatic devices havebeen generally unsatisfactory because of the problem of registeringsuccessive sheets of material in the same place in the printer. Sincesilk screen printing requires two or three printings on the same sheetto obtain the various color patterns, it is extremely important thateach time the sheet of material is placed under the screen it isregistered in exactly the same place.

The primary object of this invention is to provide a fully automaticsilk screen printing press.

Another object of this invention is to provide an automatic silk screenprinter that has positive registry over a long period of operation.

A further object of this invention is to provide an automatic silkscreen printer that increases the rate of output per man hour.

Other objects and advantages will be pointed out in, or be apparentfrom, the specification and claims, as will obvious modifications of thesingle embodiment shown in the drawings, in which:

FIGURE 1 is a side elevation of the present invention with the bed andscreen closed.

FIGURE 2 is a side elevation of the present invention with the bed andscreen open.

FIGURE 3 is taken on line 33 of FIGURE 2 showing the grippers betweenthe open bed and screen.

FIGURE 4 is taken on line 4-4 of FIGURE 1 showing the position of thegrippers with the bed and screen closed.

FIGURE 5 is a plan view of the present invention with the screen removedshowing the grippers with the paper on the bed.

FIGURE 6 is taken on line 6-6 of FIGURE 1 showing the drive mechanismfor the present invention.

FIGURE 7 is taken on line 77 of FIGURE 5 showing the position of thegripper with the screen and bed closed.

FIGURE 8 is a view of the grippers abutting the cam opener.

FIGURE 9 is a top view-of FIGURE 8.

FIGURE 10 is a top view of the gripper.

FIGURE 11 is taken on line 11-1l. of FIGURE 10 showing the gripper in aclosed position.

FIGURE 12 is a side elevation of the gripper showing the cam and camactuator in dotted line.

FIGURE 13 is a front view of the gripper in a closed position.

FIGURE 14 is taken on line 14l4 of FIGURE 11 showing the spring actuatorfor the finger.

FIGURE 15 shows the cam actuator engaging the cam to open the gripper.

The printing mechanism for this device consists of a bed It) and screen12 which are both moveable by means of linkage system 14 actuated byearns 16. The

3fi26fl9i Patented Mar. 27, 1962 ice cams are mounted on shaft 18 androtated by motor 20 and chain drive 22. The linkage system includes bellcranks 24 pivoted on pin 26. Cam follower 3i} rotatably secured to thebell crank rides on the surface of the cam actuating drive rod 32 havingone end attached to the bell crank and the other end attached to shaft36 through link 34. Eccentric arms 38 are rigidly secured to each end ofthe shaft 36 and have an arm 40 attached to one end and an arm 42attached to the other end. Arms 40 are connected to the bed iii and arms42 are connected to the silk screen frame 12. For each half revolutionof the cam 16 arm 32 will move outward from the cam rotating shaft 36.Eccentric arms 38 will rotate with shaft 36 moving bed 10 downward andsilk screen frame 12 upward. During the other half revolution of thecam, the bed and silk screen frame will be closed. Cams 16 are providedwith rapid rise-rapid fall cam surfaces so that the outward and returnmovements of the bed and silk screen frame are completed in a minimum oftime.

During the outward movement of the bed and frame, a sheet of material 28is carried to a position intermediate the bed and frame by grippers 50.The grippers are secured to drive chains 62 in sets, the number ofgrippers in each set being dependent on the width of the Sheet to beprinted. The grippers are mounted on rods 56 and 58, the former of whichis rigidly secured to end members 60 and the latter is rotatably mountedin the end members. The end members are connected to the drive chain byboss 64 so that the gripper rods are transverse to the planes of thechains. The drive chains are mounted on sprockets 66 and run between thesilk screen frame and the bed to sprockets 68 on the end of take-offtable 70. The chain then runs to drive sprockets 72 around chaintightener 74 and back to sprockets 66. The drive sprockets are mountedon the ends of shaft 92 which is secured to one-way clutch 90. Motor 29actuates a wheel and ratchet arrangement 76 through rods 80 producing areciprocating rotary motion in the wheel. This motion is carried to theclutch by chain 88 and the clutch transmits one direction of rotation toshaft 92 advancing the drive chain and free wheels in the otherdirection of rotation. The drive chain is thus advanced in a step bystep manner and in the embodiment shown in the drawings one completerevolution will be completed in five steps.

The grippers are rigidly secured to rod 56 and are provided withapertures 57 in which rods 58 are rotatably positioned. A cam E6 securedto the end of rod 58 is ac tuated on the downward movement of the silkscreen frame by an actuator 94 (FIG. 15). Rotation of rod 58 will rotatepin Q8 moving index member 61 upward against finger 100. The finger isrotatably mounted on rod 56 and biased downward by pin and springarrangement 1G2 against knurled roller 52. The upward movement of theindex member rotates the finger about rod 56 exposing the face 78 of theindex member. A sheet of material is aligned with a number of adjustableblocks 47 on the edge of feed table 46 and is inserted between thefinger and roller until it abuts the face of the index. It can be seenthat with a set of grippers mounted in a line ('FIG. 5) the sheet ofmaterial is registered in the grippers while the printer is printing onthe preceding sheet of material. On the upward movement of the frame andactuator 94, the bias of the pin and spring arrangement 102 on thefinger will rotate rod 58 and cam 96 to the initial position whileclosing the finger on the roller. The sheet of material will be clampedbetween the finger and roller and will be carried by the grippers intothe printing mechanism when the drive chain is advanced to the nextposition.

There are five sets of grippers provided on the chain drive, one foreach step of movement. It will be appreciated that any number of sets ofgrippers could be used depending only on the number of steps required tocomplete one cycle in the operation of the device. In the first step ofoperation a sheet of material is aligned with blocks 47 and registeredon the faces 78 of the index members in the grippers. When the silkscreen frame moves upward, the sheet of material will be clamped in thegrippers. As the frame reaches the top of its movement, the ratchet andwheel drive will reverse, advancing these grippers with the sheet ofmaterial into the printer. (The movement of the chain will be stoppedwith the grippers aligned along the edge of the bed10.) Since thegrippers were aligned with the feed table so that the index faces in thegrippers provide an identical registration point for each sheet ofmaterial inserted therein, positive registration is assured on the bedif the chain is moved an identical distance from the feed table to bebed in each step of movement. The chain will then be stopped with thegrippers aligned along the edge of bed 10.

The bed and frame will then close on the sheet with the grippers lyingbelow the plane of the surface of the ed (FIGURE 7). The bed is of theconventional vacuum type and will hold the sheet of material until thevacuaim is released as the bed and screen are opened. The sheet will bepulled from the screen so that the grippers can carry it to the take-offtable 70 when advanced to the next position.

As the grippers are moved across the take-off table, cam 96 will engagestationary cam actuator 106 momentarily opening the grippers in movement(FIGURE 8). The sheet of material will be released from the grippers anddrop onto a plurality of continuously moving bands 110 on the take-offtable. The grippers will be stopped on sprocket 68 below the surface ofthe take-off table so that the printed sheet will be carried clear ofthe table. The grippers will then be moved in three steps back to thestarting position.

In operation motor 20 is driven at a continuous rate of speed which canbe varied depending on the capabilities of the operator. Forapproximately one-half revolution of the motor the screen and bed areclosed while a standard mechanical squeegee is drawn across the screen.The details of mechanical squeegees are conventional and are thereforenot shown. During this half revolution of the motor, the drive from theratchet and wheel is being absorbed by the free wheeling action of theclutch. Just prior to the end of this half revolution of the motor, thebed and silk screen frame will be opened to allow the grippers to movetherebetween and Will close on the sheet registered therein. As thedirection of motion of the ratchet changes, the clutch will drive thegrippers forward one step. As the grippers approach the edge of the bednearest the take-off table, the bed and frame will start to close on thesheet of material. The grippers are then stopped and the paper isdisposed in a plane over the bed so that the bed and screen close withthe sheet therebetween.

The reach of the drive chain from the feed table to the point ofregister with the bed is tight at all times, assuring positiveregistration from one position to the other. It is conceivable that thegrippers be raised over the bed but this would introduce some slack inthe chain which will reduce the possibility of obtaining positiveregister in each step of operation. It will be appreciated that theremust be some vertical motion of either the bed or the chain to allow forproper clearance for the grippers.

After the printing operation the bed and frame are opened to allow thegrippers to move across the take-off table carrying the printed sheetout from the bed. The sheet will have a tendency to stick to the silkscreen and by moving the screen away from the printed sheet the vacuumbed has a tendency to peel the material from the screen. This peelingeffect can be increased by raising the silk screen frame at an anglerather than horizontally as shown by increasing the length of eccentricarms 38 at the gripper end of the bed so that one end of the frame ismoved through a greater distance than the other end. The preferablearrangement is to have the end next to the gripper raised the highest sothat the motion of the grippers will pull the sheet from the screen. Thegrippers are momentarily opened by actuator 1% as they are moved acrossthe take-01f table releasing the printed sheet. The sheet will then becarried clear of the grippers by the bands to an automatic dryer.

This device can be used for material other than paper, such as cardboardor even metal sheets. As presently set up, the grippers can handle stockfrom three-thousands of an inch to the thickness of corrugated boardwithout any adjustment. It is possible to increase this to quarter inchstock with a very minor adjustment in the grippers.

Although but one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. In a sill; screen printing device for producing successive inkedimpressions in like predetermined locations on each of a plurality ofsheets of stock comprising, a fiat bed defining a hard smooth uppersurface for receiving and supporting one of said sheets, printing meanspositioned in a plane parallel to the plane of the bed, means forraising the bed vertically upward and lowering the printing meansvertically downward into engagement simultaneously, means forregistering a sheet in a predetermined position on one side of the bed,said registering means including means for clamping the sheet, meanssecured to the printing means and movable therewith for actuating theclamping means to receive one of said sheets only When the bed andprinting means are in engagement, said clamping means closing on thesheet when the bed and printing means are opened, and means for movingthe registering means to a printing position between the bed andprinting means, said bed and printing means closing on the sheet whenthe registering means is in the printing position.

2. In a silk screen printing device according to claim 1 wherein theclamping means comprises a number of grippers positioned on a pair ofbars, one of said bars being rotatable within the grippers, a cam on theend of said rotatable bar actuated by the actuating means, an indexblock in each gripper connected to the rotatable rod and movable by saidcam to open the gripper, said blocks presenting an indexing surface forregistering said sheet when the gripper is opened by the actuatingmeans.

3. In a silk screen printing device for producing successive linkedimpressions in like predetermined locations on each of a plurality ofsheets of stock comprising, a fiat vertically movable bed defining ahard smooth upper surface for receiving and supporting a sheet,vertically movable silk screen printing means positioned over the bed,means for registering one of said sheets on one side of the bed, meanson the other side of the bed for transporting the sheets away from thebed, means for intermittently moving the bed and printing meansvertically into and out of engagement, a pair of endless chains mountedto move in one direction past the registering means, between the bed andprinting means and over the transporting means, means for advancing thechain in a step by step manner, said advancing means being operable onlywhen the bed and printing means are out of engagement, gripper meansmounted between the chains at intervals so that one section is alignedwith the registering means, one section is aligned with the bed, and onesection is aligned with the transporting means at the end of each stepof movement, means supported by the printing means and movable therewithfor actuating the gripper means while aligned with the registeringmeans, so that one of said sheets on the registering means can beclamped within the gripper, whereby on opening of said printing meansthe gripper will close on the sheet and carry the sheet between the bedand printing means and on the next step of movement the sheet will becarried to the transporting means.

4. An automatic silk screen printer comprising a movable bed, a silkscreen mounted above the bed in a plane parallel to the plane of thebed, said screen being connected to the bed to move oppositely to themovements of the bed, means for actuating the connecting means to movethe bed and screen simultaneously towards each other to a closedposition and away from each other to an open position, a pair ofcontinuous chains mounted to ro tate in planes parallel to each otherand transverse to the planes of the bed and screens, a plurality ofgripper sections having one end attached to each chain, means carried byand movable with the screen for opening one of the gripper sections toreceive a sheet of blank material when the bed and screen are in theclosed position said means for actuating the connecting means advancingthe chain simultaneously with the opening of the bed and screen so thatthe sheet of material is positioned between the bed and screen duringthe period of time it takes to move the bed and screen from the closedposition to the open position and back to the closed position.

5. A printer according to claim 4 wherein the actuating means includes aratchet and wheel, means for reciprocally actuating the ratchet andwheel, a one-way clutch mounted to actuate the chain, and meansconnecting the ratchet and wheel to the one way clutch so that the chainis advanced intermittently by the clutch.

6. An automatic silk screen printer comprising a movable bed, a movablescreen positioned in a plane parallel to the plane of the bed, means formoving the bed and screen relative to each other, a pair of continuouschains movable in planes parallel to each other and transverse to theplanes of the bed and screen, means for advancing the chain in stages, agripper section secured to the chains in each stage of movement, eachgripper section having a pair of parallel rods mounted transverse to theplanes of the chain, a plurality of grippers rigidly secured to one ofsaid rods, the other rod being rotatable, a cam secured to the end ofthe rotatable rod, a finger rotatable on the stationary rod, a springbiasing the finger toward the rotatable rod, an index block slidablewithin the gripper operatively engaging the finger, a pin secured to therotatable rod and engaging the block so that on actuation of the cam therod will rotate and the pin will force the block upward against thefinger, said block providing an indexing means for aligning sheets ofblank material, means mounted on the silk screen for actuating the camupon closing the screen, said means releasing the cam when the silkscreen is open so that the fingers will grip the sheet of material, andsaid advancing means advancing the grippers to a position between thebed and the screen.

7. In a silk screen printing device for producing successive inkedimpressions in like predetermined locations on each of a plurality ofsheets of stock comprising, a flat bed for receiving and supporting oneof said sheets, a silk screen positioned over and connected to the bed,registration and gripping means movable to a station for reception ofmaterial, means for moving the registration and gripping means to apredetermined location with respect to the bed so that a sheet carriedby the gripping means will be positioned in a predetermined location,means for closing the bed and screen while the sheet is on the bed, saidclosing means opening the bed and screen after printing by raising theend of the screen adjacent the grippers to a greater height than theother end of the screen, and means for moving the sheet to a dischargepoint for releasing the sheet to a take-off means the motion of movingmeans being effective to peel the sheet from the screen.

References Cited in the file of this patent UNITED STATES PATENTS1,589,546 Nichols June 22, 1926 1,966,416 Parmele et a1. July 10, 19342,196,678 Klopfenstein Apr. 9, 1940 FOREIGN PATENTS 800,680 France July16, 1936

